[AMDGPU][MC][NFC][DOC] Updated AMD GPU assembler syntax description.

Summary of changes:
- Added f16 omod modifier (bug 51386).
- Corrected names of data types (bug 48638).
- Enabled a16 with most GFX10 MIMG opcodes (see https://reviews.llvm.org/D102231).
- Corrected description of integer operands (bug 51130).
- Corrected description of 8-bit DS offsets (bug 51536).
- Improved PERMLANE op_sel description.
- Corrected *SAD* opcode types.

GitOrigin-RevId: 8ea3e9d9a2640097e10fe0bc80a0d670831bced6
diff --git a/docs/AMDGPU/gfx8_vdst_7.rst b/docs/AMDGPU/gfx8_vdst_7.rst
new file mode 100644
index 0000000..f47e838
--- /dev/null
+++ b/docs/AMDGPU/gfx8_vdst_7.rst
@@ -0,0 +1,20 @@
+..
+    **************************************************
+    *                                                *
+    *   Automatically generated file, do not edit!   *
+    *                                                *
+    **************************************************
+
+.. _amdgpu_synid_gfx8_vdst_7:
+
+vdst
+====
+
+Image data to load by an image instruction.
+
+*Size:* depends on :ref:`dmask<amdgpu_synid_dmask>` and :ref:`tfe<amdgpu_synid_tfe>`:
+
+* :ref:`dmask<amdgpu_synid_dmask>` may specify from 1 to 4 data elements. Each data element occupies 1 dword.
+* :ref:`tfe<amdgpu_synid_tfe>` adds 1 dword if specified.
+
+*Operands:* :ref:`v<amdgpu_synid_v>`